Liquid crystal displays (hereinafter, referred to as LCDs) have been widely used as flat-panel displays ranging from small-size devices to those having a large display capacity. However, these LCDs have the viewing angle characteristics that the display characteristic becomes bad, when it sees from an angle; for example, contrast falls or glay-scale inversion which brightness reverses within glay-scale occurs. Therefore, there have been strong demands for solving these problems.
Recently, with respect to an LCD system for improving these viewing-angle characteristics, a vertically aligned nematic type liquid crystal display (hereinafter, referred to as VA-LCD) has been developed, for example, as disclosed in Japanese Patent No. 2548979. As described at pages from 845 to 848 in SID 97 DIGEST, it has been known that the VA-LCD has an arrangement in which two negative uniaxial phase retarder films having optical axes in a direction perpendicular to the film surface are placed above and below liquid crystal cells so that it becomes possible to provide a characteristics of a wider viewing-angle, and in this LCD, a uniaxially oriented phase retarder film having a positive refractive index anisotropy having an in-plane retardation value of 50 nm is used so that a characteristics of wider viewing-angle can be achieved. A phase retarder plate in which a negative uniaxial orientation phase retarder film having an optical axis in a direction perpendicular to the film surface and a uniaxial orientation phase retarder film having a positive refractive index anisotropy are combined to provide the same optical properties as a biaxial orientation phase retarder film as a whole.
Moreover, in addition to VA-LCDs, for example, it has been know that a method in which a biaxially oriented phase retarder film is used in a 90-degree twisted nematic liquid crystal display so as to improve the viewing angle. It has been known that the biaxially oriented phase retarder film is obtained by biaxially drawing a film made from a thermoplastic polymer. With respect to an apparatus to be used for the biaxial orientation, an experimental apparatus which can biaxially draw a piece of film or a simultaneous biaxially drawing machine which has been conventionally used for producing packaging films and the like have been known; however, in the experimental apparatus, it is difficult to produce a large amount of phase retarder films that are sufficiently large films adequate to LCDs; in contrast, the simultaneous biaxially drawing machine can not achieve evenness in the retardation value that is sufficiently applied to the LCD, evenness in the slow axis direction and surface properties (without scratches) in a large area. Moreover, when a conventional drawing machine for producing phase retarder films used for LCD is used, although sufficient evenness is obtained in a large area, the resulting optical properties only have a very limited range in its biaxial orientation.